How does the 5 Point leveling compare to (10x10)Grid leveling.. sounds like a simpler version of the same thing.

It is.

3-point levelling can cope with a bed that is flat but not level (tilted in 2 directions).

4-point levelling can cope with a bed that is flat but not level, and additionally a twist in one axis that causes the bed tilt to vary uniformly with X and/or Y position. Or a bed that would be flat except that it has a uniform twist in it.

5-point levelling is designed to handle a bed that is basically flat but has a uniform bulge or depression. centred on the centre of the bed. Or more commonly, the bed is flat but the print head dips slightly near bed centre because of bending in the gantry that carries the print head.

The primary purpose of grid-based levelling as I see it is to compensate for beds that are not flat.

How does the 5 Point leveling compare to (10x10)Grid leveling.. sounds like a simpler version of the same thing.

It is.

3-point levelling can cope with a bed that is flat but not level (tilted in 2 directions).

4-point levelling can cope with a bed that is flat but not level, and additionally a twist in one axis that causes the bed tilt to vary uniformly with X and/or Y position. Or a bed that would be flat except that it has a uniform twist in it.

5-point levelling is designed to handle a bed that is basically flat but has a uniform bulge or depression. centred on the centre of the bed. Or more commonly, the bed is flat but the print head dips slightly near bed centre because of bending in the gantry that carries the print head.

The primary purpose of grid-based levelling as I see it is to compensate for beds that are not flat.

D.C. So should Auto bed compensation run from DWC work with 3 points or are we talking about something completely different?

That's what I thought but when I run it, the values aren't reported by DWC. To be clear, the points are front left, centre rear, front right in a clockwise direction. These get probed as expected but I don't get the normal "Bed Equation fits points….etc" that I do when I run 4 point compensation. There is nothing reported in the G-code console.

Just wanted to add that this a brilliant tool to use for initially getting the bed level if you have a 3 point levelling system. Just set the probe points as close as you can to where the levelling screws are and run the check. Leave one screw alone and adjust the others until the readings are as close as you can get it. I found it much easier than messing around with bits of paper or drill bits. Once set, you can always go back to 4 or 5 or more points is you want to.